Analysis of artisanal fishing effort in San Nicolás, Paraná River delta, Argentina
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Analysis of artisanal fishing effort in San Nicolás, Paraná River delta,
Argentina
JORGE LIOTTA
Dirección de Planificación y Gestión de Pesquerías, Subsecretaría de Pesca y Acuicultura, Ministerio de
Agricultura, Ganadería y Pesca de Argentina, Ciudad Autónoma de Buenos Aires, Argentina
Museo de Ciencias Naturales “Antonio Scasso”, San Nicolás, Buenos Aires, Argentina.
* Corresponding author: jorgerliotta@gmail.com
Abstract. River fisheries in La Plata river basin in Argentina are very important, both in social
and economic terms. Published data about quantification of the effort carried out by fishermen
is very scarce, although this information is key to evaluate the total effort of this activity. The
objective of this work is to present data referred to fishing effort, obtained from the activity of a
group of fishermen which land their catches in San Nicolás city, in the north of Buenos Aires
province. Their dedication to work is diverse: some are completely dedicated to the activity; for
others, fishing is complementary to other works, such as construction. Others in addition, care
for or possess cattle in wetlands. The mean dedication to fishing was 158.9 ± 53.9 days worked
per year, with a median value of 131. The median of the CPUE is 104.4 kg per fisherman and
day, or 13.6 tn per fisherman and year. The dispersion of the values is high. Factors related with
environmental and climatic phenomena, demand for fish and operational aspects, modulate the
time invested in fishing.
Key words: small-scale inland fisheries, CPUE.
Resumen: Análisis de la dedicación a la pesca artesanal en San Nicolás, delta del río
Paraná. Las pesquerías fluviales de pequeña escala de la cuenca del Río de la Plata en
Argentina son significativamente importantes en términos sociales (como aportes a la seguridad
alimentaria y a las economías familiares) y económicos. Son muy escasos los datos publicados
sobre la cuantificación del esfuerzo efectuado por los pescadores, aunque esta información es
clave para evaluar la magnitud de la actividad. El objetivo de este trabajo es presentar datos de
dedicación a la pesca artesanal, y analizar la influencia de diversos factores sobre aquella, de un
grupo de pescadores de cauce del Delta del Paraná, que desembarcan sus capturas en San
Nicolás, en el extremo norte de la provincia de Buenos Aires. La dedicación a la pesca fue de
158.9 ± 53.9 días trabajados por año, con una mediana de 131 días. La mediana de la CPUE del
período fue de 104.4 kg/pescador.día, o 13.6 tn/pescador-año, utilizando ambas medianas. Todos
los valores mostraron una amplia dispersión. Algunos pescadores se dedican por completo a la
actividad; otros, la complementan en proporciones variables con tareas como el cuidado de
ganado vacuno en zona de islas, la construcción o diversas tareas temporarias. Factores
relacionados con fenómenos ambientales (variaciones de nivel hidrométrico) y climáticos
(fuertes vientos), disponibilidad y demanda de pescado y aspectos operativos modulan la
dedicación a la pesca.
Palabras clave: pesquerías continentales de pequeña escala, CPUE.
Introduction they use only manual work in capture, processing,
River fisheries in the Río de la Plata basin in distribution and marketing of resources, they are
Argentina are of a small-scale or an artisanal type: usually practiced by individuals, family or
Pan-American Journal of Aquatic Sciences (2020), 15(3): 218-225
Artisanal fishing effort in Paraná River delta 219
community groups settled in coastal communities or city (33°20'S, 060°15' W) was recorded daily for
riverside, from boats with little autonomy, and worth 588 days (from October 2016 to May 2018).
arts and techniques of minimum modernization Biweekly, semi-structured interviews (Diaz
(Parlatino 2017). Small-scale fisheries are Bravo et al. 2013) were conducted. For this purpose,
significantly important in social (contributing to an "interview guide" was prepared, with questions
food security and family economies; Araya et al. grouped by topic, aimed at gaining knowledge about
2009; FAO 2015) and economic terms (generating aspects of the activity, on two-time scales: the last
genuine revenue cushioning crises situations; Mahon fishing trip (corresponding to the landing present at
1997; FAO 2005; Daw et al. 2009). However, in the time of the survey) and the previous two weeks.
most of temperate and tropical river systems, Questions concerning the last fishing trip refer to: (i)
information on this activity is fragmentary and landing composition and volume, (ii) fishing gear,
sparse, generating an underestimation of its (iii) gear modality and intensity of use, (iv) aquatic
magnitude, and therefore insufficient consideration body -river, lagoon, among others- in which each
by government administrations (Castello et al. 2007; gear was used, and (v) duration of trip in days. The
Welcomme et al. 2010; FAO 2018). topics asked for the previous two weeks were: (i)
The time invested by fishermen in obtaining dedication to other works and (ii) elements that
their catch, known as fishing effort, is a key hindered fishing.
parameter to evaluate the magnitude of this activity. For each fisherman, the number of landings
The designation of professional or full time, part- carried out (L) and mean time (=fishing effort, FE,
time and occasional fishermen is usual; FAO (2016) in days) of an individual trip were calculated. The
estimates that by 2014, 36% of fishermen engaged in annual fishing effort (AFE) was obtained. It is
the activity as full-time, 23% part-time and the rest defined as AFE = L * FE. The values were obtained
were occasional or without specifying situation. for the whole period of study and standardized to
Different criteria can be used to justify this 365 days. The number of landings that occurred per
classification (Welcomme 1992, OIT 2003): time day and per week, and the days with increased
spent in activity; occasion of fishing (for special frequency of landings were also obtained.
celebrations, for example); percentage of revenue Values of catch per unit effort (CPUE), in kg
earned from fishing; destination of the fish (own or per fisherman and day (kg/fisherman.day) and %
community consumption, sale); number and were calculated for the most representative species
complexity of the fishing gear used. of this fishery: sábalo Prochilodus lineatus, boga
For inland fisheries in Argentina, only few Megaleporinus obtusidens, patí Luciopimelodus
authors mention proportions of fishermen with pati, armado común Pterodoras granulosus, dorado
different dedication. In Paraguay river, 44% of 3,300 Salminus brasiliensis, surubí pintado
fishermen were full-time (Espinach Ros & Delfino Pseudoplatystoma corruscans, and for the total
1993). For lower Paraná alluvial plains fisheries, catches for each time a fisherman was interviewed.
fishermen spent, on average, 50% of their time to Graphs of water level (WL) of San Nicolás
fishing, ranging from less than 25% to 90% port since October 2016 to May 2018 were made
(Espinach Ros & Fuentes 2000). In the province of using data from the Prefectura Naval Argentina
Corrientes, Iwaszkiw (2001) mentions that 62.5% of website
640 fishermen were full time, and 37.5%, part time. (https://contenidosweb.prefecturanaval.gob.ar/altura
These works, however, do not identify the criteria s/index.php). For the same period, daily weather
used for classification. conditions (temperature, precipitation, and wind
The objective of this work is to present data intensity) data was obtained from the Experimental
on CPUE and fishing effort, obtained from the Station of Instituto Nacional de Tecnología
record of the activity of a group of fishermen from Agropecuaria San Pedro
San Nicolás, at the northern end of Buenos Aires (https://inta.gob.ar/documentos/informacion-agro-
province. Variables that limit fishing are described meteorologica-eea-san-pedro), located about 64 km
and analyzed. SE from San Nicolás.
Materials and methods Results
The arrival of fishermen to land their catches There are about 25 active fishermen in San
in a sector called "Paseo Costanero" in San Nicolás Nicolás (recent official statistics on these values
were unavailable). The activity develops throughout
Pan-American Journal of Aquatic Sciences (2020), 15(3): 218-225
220 J. LIOTTA
the year. Fishermen work in the main channel of fisherman is presented (and summarized in Table II)
Paraná river and adjacent wetlands, in an from data obtained during 87 interviews (in 36 dates
approximately semicircular area with a radius of 15 from the period).
km from the landing site. There, around 10 Fisherman 1 and 2 had a similar fishing mode.
fishermen sell their catches in individual stands. At Both were highly dedicated fishermen, although they
early morning, the fishermen land their catches, also owned livestock in wetlands, where they
obtained from the previous hours, or on few permanently reside. Most of them used nets, such as
occasions from two days prior; one of them passive fishing gear in lagoons, and dragging in the
(identified here as fisherman 7) landed just one day a main channels. They sold fish mainly to the public,
week (on Sunday) but fishes 3 or 4 days per week. although in times of plenty, they delivered part of
The values of AFE are shown in Table I. Three of their catch to "acopiadores” (collectors that sell in
the fishermen were not considered in this analysis local markets or for export). Fisherman 3 was
since landed their catches less than 5 times in the exclusively dedicated to fishing, being specialist in
period (and so they were considered here as the use of hook gears (although sometimes used also
occasional fishermen). different nets); in general, he fished less days than
The resulting statistics for AFE are (in days of the previous two; their catches had a great diversity,
work per year): mean = 158.9; standard deviation = with prices on average higher than that of the most
53.9; first quartile = 128; median = 131 and third common species (sábalo). He sold exclusively to the
quartile = 204.1 (Fig. 1). public. Fishermen 4 and 5 showed a variable
A maximum of 7 fishermen worked dedication to fishing, with periods of intense activity
simultaneously on the site, being more frequent the interspersed with times almost without presence in
presence of 2 during the period (Fig. 2). Almost 10% their stands. They fished in environments of the
of the days there was no activity. The days with most alluvial valley near the landing site and their
landings were Saturday, Sunday and Friday in equipment was more limited than that from the
descending order. Those days, the average number previous ones: for them, fishing is an activity that
of three fishermen with landings was exceeded (Fig. takes place in times when more money is needed, or
3). The minimum frequency of landings was on when catches are especially abundant or profitable.
Monday. They sold to the public, although they sometimes
The median of the CPUE for all the fishermen delivered fish to collectors. Fisher 6 specialized in
and the whole period was 104.4 kg landed per the capture of large, valuable specimens, such as
fisherman and day (Q1=83.5; Q3=137.7). The main surubí pintado and dorado: he worked exclusively in
species was sábalo (54%), followed by patí (12%) the main course, with passive nets located deep in
and boga (7%). The former two species were backwaters, or long lines with large hooks; as
captured all the year. CPUE of boga and armado fishermen 1 and 2, he owned cattle; in winter (when
común were greater in autumn and spring (with their preferred species are less abundant) very little
differences between years). Dorado and surubí time was devoted to fishing. He sold to the public, or
pintado were caught mainly in summer, although in (on request) to fish restaurants. Fisher 7 landed his
small numbers and percentages (Fig. 4). catch only on Sunday, but fished at least three days a
The annual CPUE obtained was 13.6 week and sometimes even with more than one
tn/fisherman.year (using the median values for daily canoe; he worked with helpers; as a result, his
CPUE and AFE). A brief description of each landings were much larger than those of all previous;
Table I. Parameters used to calculate the time invested in fishing.
Parameter Unit 1 2 3 4 5 6 7 Mean
N Total landings number 318 323 189 203 210 141 85 -
L Landings / year 197 201 117 126 130 88 53 130.3
L% Landings / year (%) 54% 55% 32% 35% 36% 24% 14% 35.7%
FE Worked days / landing 1.13 1.14 1.12 1 1 1 3.5 -
AFE Worked days / year 223 229 131 126 130 88 186 158.9
AFE% Worked days / year (%) 61% 63% 36% 35% 36% 24% 51% 43.5%
Pan-American Journal of Aquatic Sciences (2020), 15(3): 218-225
Artisanal fishing effort in Paraná River delta 221
he sold to the public, although he sometimes
delivered part of the catches to collectors. Fishermen
8 and 9, who landed less than 5 times in the period,
were not included in the study, nor fisherman 10,
who generally got their fish from fishermen from
other places.
The sequence of certain meteorological and
hydrological parameters and the weekly frequency
of landings is observed in Figure 5.
Specific events of heavy rainfall (end of
December 2016, February 2018), strong winds (end
of August 2017) (see Fig. 5 A and B) or persistent
fog hindered fishing, are related with low frequency
of landings.
Discussion
The effort and the catch values obtained allow
characterizing the magnitude of the fishery. The AFE
Figure 1. Boxplot of annual fishing effort (in days per obtained is variable, with 158.9 ± 53.9 days worked
year). Diamond: mean value. per year, and a median value of 131 day/year. These
are the first concrete values of fishing effort for this
small-scale fishery.
The CPUE values obtained (104.4
kg/fisherman/day) agree with the values of “more
than 110 kg” mentioned by Quirós et al. (2007) for
the lower middle Paraná.
Most of the fishermen showed important
fluctuations in their landing frequency over the
whole period. This was caused by various factors:
some fishermen are completely engaged to the
activity; others complement it in varying proportions
with tasks like cattle care in wetlands, construction
or diverse temporary works.
Among the causes that modulate frequency of
Figure 2. Number of landings per day of the week. landings, the environment imposes some of them. At
the beginning of the period, with the WL fluctuating
around 2.5 m, the level which surpasses the bankfull
level (therefore connecting the main channel to the
floodplain), landings were more numerous. From
mid April 2017 onwards there was a period of high
WL and low air temperatures, which coincided with
fewer landings. The WL remained high since the
beginning of 2018 until the end of the analysis
period, coinciding again with lower frequency of
landings. For fishermen, the greater difficulty of
catching fish in situations of large flooded areas is
clear and predictable, as well as the ease of catching
them in lagoons and canals in low waters. The
inverse relationship between fishing intensity
Figure 3. Percentage frequency of the number of (expressed here as landing frequency) and the NH in
fishermen landing per day. floodplain rivers, mentioned by Neiff (1999) and
Arthington et al. (2004), is confirmed here. Strong
Pan-American Journal of Aquatic Sciences (2020), 15(3): 218-225222 J. LIOTTA
Figure 4. CPUE (in percentage) for the main species landed in San Nicolás from oct-16 to jun-18.
Table II. Characterization of the fishermen. The notation +, ++, +++, ++++ refers to a scale of increasing relative value.
Catches’ destination
Annual
Restaurant
Use of Fishing gears Landing
Collectors
N Seasonality fishing effort Other activities
Public
habitats diversity volume
(% of a year)
1 Both All year 61% Cattle ++ +++ +++ +
2 Both All year 63% Cattle ++ +++ +++ +
3 Channel All year 36% No +++ ++ ++++
When jobless or Construction,
4 Floodplain 35% + ++ ++ ++
high catches others
When jobless or Construction,
5 Floodplain 36% + ++ ++ ++
high catches others
6 Channel All year 24% Cattle + + ++ ++
7 Both All year 51% No +++ +++ +++ +
Pan-American Journal of Aquatic Sciences (2020), 15(3): 218-225Artisanal fishing effort in Paraná River delta 223
Figure 5. A) Daily mean wind intensity; B) daily rainfall; C) Mean weekly air temperature; D) water level (at 2,5 m,
the WL surpasses the bankfull level, connecting the main channel to the floodplain); E) weekly landings frequency.
winds, persistent fog and heavy rainfall can also their migration stages: boga in autumn, silverside
reduce the frequency of landings. Odontesthes bonariensis during winter and armado
Other environmental causes that reduced común in autumn and spring; the most valuable
landings were the abundance of piranhas species, dorado and surubí pintado, are mainly
(carnivorous fish of the family Serrasalmidae, which caught in summer. There is also a significant
can break nets especially in summer times) and the increase in the demand for fish at Easter (coincident
drift of branches, water hyacinths, and debris with the upward migration of several species). It is
(mainly during high WL). common for fishermen to work more intensively
In this region, channel fisheries are several weeks before, storing their catches, because
particularly active during upstream and downstream collectors and the public buy more these days.
migration of fishes (Segura & Delfino 1991; Finally, a monthly fluctuation was mentioned,
Espinach Ros & Delfino 1993). This results in associated by fishermen to a lower availability of
increases in the demand for certain species during money from consumers at the end of each month.
Pan-American Journal of Aquatic Sciences (2020), 15(3): 218-225224 J. LIOTTA
Inconveniences of the fishermen themselves, & Petr, T. (Eds.). Proceedings of the second
such as health problems or difficulties with their international symposium on the
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activity. islas del departamento de Victoria, Entre Ríos.
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transfer of cattle, increase in the demand for labor in Castello, L., Castello, J. P. & Hall, C. A. S. 2007.
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Acknowledgements Ed. Med., 2(7): 162-167.
To Mr. Ramón Carabajal (†) for kindly Espinach Ros, A. & Delfino, R. 1993. Las
helping in the record of data used in this work. To pesquerías de la cuenca del Plata en Bolivia,
Beatriz Giacosa, for her involvement in the Paraguay, Argentina y Uruguay. Pp 36-51 .
execution of tasks on the site, in conducting surveys Anexo IV. Informe de la sexta reunión del
and suggestions for an earlier version. To Ariana Grupo de Trabajo sobre Recursos
Liotta for her help in the English translation. To all Pesqueros. Montevideo, Uruguay. FAO
the fishermen and helpers for sharing their Informe de Pesca. No. 490. Roma. 80p.
experiences and contributing data to this analysis. To Espinach Ros, A. & Fuentes, C. 2000. Los recursos
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Received: October 2019
Accepted: June 2020
Published: September 2020
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